Apparatus for string polishing work pieces



Aug. 16, 1960 R. F. RULE APPARATUS FOR STRING POLISHING WORK PIECESFiled Feb. 24, 1959 5 Sheets-Sheet 1 FIG.

INVENTOR. RICHARD F. RULE ATTORNEY Aug. 16, 1960 R. F. RULE 2,948,996

APPARATUS FOR STRING POLISHING wosx PIECES Filed Feb. 24, 1959 sSheets-Sheet 2 FIG. 5

V N s RICHARD FI.NFUTRE ATTORNEY Aug. 16, 1960 R. F. RULE APPARATUS FORSTRING POLISHING WORK PIECES 5 Sheets-Sheet 3 Filed Feb. 24, 1959INVEIIVTOR. RICHARD F. RULE ATTORNEY Aug. 16, 1960 R. F. RULE 2,948,996

APPARATUS FOR STRING POLISHING WORK PIECES Filed Feb. 24, 1959 5Sheets-Sheet 4 w, I F/a.a

FIG /0 F-, RICHARD R NVQSTERE BY f W A T TOR/V5 Y Aug. 16, 1960 R. F.RULE 2,948,995

APPARATUS FOR STRING POLISHING WORK PIECES 5 Sheets-Sheet 5 Filed Feb.24, 1959 INVENTOR. RICHARD F. RULE ATTORNEY eiay-d. V

States APPARATUS FOR STRING POLISHING WORK PIECES Filed Feb. 24, 1959,Ser. No. 795,007

6 Claims. (Cl. 51-145) 1 EMj-y invention con ists in a new and usefulimprovement in apparatus for string polishing work pieces, and isdesigned more particularly or polishing the ball groove of the innerring of a ball bearing or a similar object, when abrasive-impregnatedstring rs used. It provides grim automatic operation which will be cutoil in the event of failure to feed the work pieces, or loss of tensionof the string. My apparatus is unique in that all ofi-ts operativeelements are actuated by rotation of a single drive disc, thussynchronizing operation of all P rt }While I have illustrated in thedrawings and hereinafter fully describe one specific embodiment of myinvention, it is to be distinctly understood that I do not consider ty-invention to be limited to said embodiment, but refer for its scope tothe claims appended hereto.

{ In the drawings:

lis a fragmentary perspective of the upper portion of myfapparatus.

Fig. 2 is an enlarged horizontal section on the line 2-4 of Fig. 1, inthe direction of the arrows.

Fig. 3 is a detail of the cam and roller for oscillation of the mandrel.1

Fig. 4 is an elevation of one end of the apparatus, the casing beingshown in section.

Fig. 5 is a vertical section on the line 5-5 of Fig. 4, in the directionof the arrows.

' Fig. 6 is an elevation of the other end of the apparatus, the partsbeing in diiferent positions, the casing being shown in section, and thefeed mechanism being omitted.

Fig. 7 is a vertical section on the line 7-7 of Fig. 6, inthe directionof the arrows.

j Fig-8 is an enlarged detail of the mandrel in position for the feedmechanism to mount a work piece on the mandrel.

f Fig. 9 is an enlarged detail showing the feed mechanism retracted andthe mandrel and work piece positioned for spinning the work piece to bepolished.

@Fig. 10 is an enlarged detail showing the mandrel disposed to strip thepolished work piece therefrom. -Fig..ll is a greatly enlarged detailshowing the forwarding .rollers for the string, and means foroscillating thestring.

Fig. 12 is a top plan of the work piece hopper.

Fig. 13is a vertical section on the line 13-13 of Fig.

12, in the direction of the arrows.

Fig. 14 is a perspective of the work piece hopper, part broken away, andthe feed chute. i As shown in the drawings, my improved apparatus hasafcasing C having a front wall 1, a rear wall 2, end walls? and 4, abottom 5 and a top 6. A horizontally disposed shaft S is suitablyjournaled in the walls :1 and 2 (Figs. 4, 5, '6 and 7) with a pulley S-1thereon for rotating the shaif t S by a belt from a suitable primemover, such as an electric motor (not shown). A drive disc D is fixed onthe shaft S in the casing C. The disc D has a peripheral bevel D 1.

A horizontally disposed post 7 is mounted on the wall 21(Figs. 1 and 2)on which a sleeve 8 is slidably mounted. The-sleeve 8 has a median,transverse wall 8-a.

atent 2,948,995. Patented Aug. 16, 1960 w 2 An expansion spring 9 in thesleeve 8 bears against the post 7 and a ball bearing 8-b mounted in thesleeve 8 against one side of the wall 8-a. A mandrel M has its inner endM-1 received in the sleeve 8 against a ball bearing 8-c mounted againstthe other side of the wall 8-a. The mandrel M is journaled in a ballbearing M-2 which is journaled by pins P in slots P-1 in a hanger M-3pivotally mounted on the under side of the top. 6 of the casing C (Figs.1, 2 and 3). The hanger M-3 has a depending finger M-4 carrying a rollerM-S. The drive disc D has an arcuate cam D-2 on its rear face (Figs. 2and 3) with portions D-3 and D-4 to coac-t with the roller M-5 tooscillate the mandrel M. The mandrel M has its forward end M-6 journaledin a bore 1-a in the wall 1, and a conical stripper abutment 1-b isformed at the outer end of the bore 1-a. The mandrel M has a conical camM-7 co-acting with the bevel D-1 of the drive disc D, as a cone clutchwhereby the mandrel M is rotated when it is projected forwardly by thespring 9 into contact with the rotating drive disc D (Fig. 9).

I will now describe the mechanism for feeding the work pieces W to themandrel M. A hopper H (Fig. 4) above the top 6 of the casing C ismounted on one end by a ball and-socket joint H'1 on the upper end of apitman H-2 journaled on a crank H-3 on the end 5-2 of the shaft Spassing through the rear wall 2 of the casing C. A feed chute F ishinged on the other end of the hopper H, extends downwardly outside ofthe wall 1 of the casing C (Fig. 4), and has, at its lower end, alateral arm F-l slidable in a socket F-2 in the wall 1 (Figs. 4, 8, 9and 10). The arm F-1 has mounted on its end a pin F-3 whichpassesthrough the socket F-2, and a bore F-4 in wall 1 at the inner end of thesocket F-Z, and carries on its end a roller F-S. A contraction springF-6 coiled about the pin F-3 and attached to the arm F at one end and tothe wall 1 at its other end, biases the roller F-5 against the frontface of the drive disc D. The drive disc D (-Fig. 2) has on its frontface a cam groove D-5 with portions D-6 and D-7 co-act-ing with springF-6 to cause oscillations of the feed chute F.

The feed chute F has a discharge throat F-7 co-axial with the mandrel M.It will be noted (Fig. 8) that the 'feed chute F and its dischargethroat F-7 are so dimensioned and related that the work pieces move fromthe hopper H, edgewise through the chute F and sidew-ise through thethroat F-7 so that their bores W-1 are so disposed that the pieces W canbe mounted on the conical end M-6 of the mandrel M in a tight fit (Fig.9).

-I will now describe the mechanism for placing the abrasive-impregnatedstring A on the work pieces W. A strut 10 is mounted on the end walls 3and 4 slightly above the bottom 5, in the casing C. A pair of roners 11and 12 are journaled on the strut 10 above an 01'lfi\. 13 in the bottom5 of the casing C. A second pair of rollers 14 and 15 are journaled onthe strut 10 above an orifice 16 in the bottom 5. Arcuate segmentalracks 17 are mounted on the rear face of the drive disc D and co-actwith pinions 11a and 14-a on the rollers '11 and 14, the rollers 12 and15 being pressure idlers. A strut 18 is mounted on the end walls 3 and 4of the casing C slightly above the strut 10. A pair of hollow shafts 19and 20 are journaled in the strut 18 and the wall 1, carrying radialhollow tubes 21 and 22, respectively, disposed outside of the casing C.These tubes 21 and 22 have openings 21-a and 22-11, respectively on thesides at their outer ends. Segmental rack sections 23 and 24 areremovably mounted on the periphery of the drive disc D and co-act withpinions 19-a and 29-a on the shafts 19 and 20, respectively, tointermittently rotate shafts 19 and 20. It is obvious that, as abovementioned, the number of revolutions of the tubes 21 and 22 by ro.

tation of the shafts 19 and 20 can be determined by the number ofsections 23 and 24.

A frame R (Figs. 1 and 2) is vertically slidable in slots 1-c in thefront wall 1, and carries a pair of freely rotating, grooved rollers R-loutside of casing C, disposed on either side of the mandrel M. The frameR (Fig. 1) is so disposed relative the drive disc D as to be raised bythe passage along the bottom of the frame R of a pin R-2 received in oneof the holes R-3 in the rear face of the drive disc D. The frame R dropsby gravity after passage of the pin R-2.

The string A passes from a spool A-l (Fig. 11), through the orifice 13into the casing C, to and between the rollers 11 and 12, to and throughthe hollow shaft 19, through the tube 21 and out of same through theopening 21-a outside of the casing C, to and over the rollers R4, to andthrough the opening 22-a, through the tube 22 and through the shaft 20,into the casing C, to and between the rollers 14 and 15, and through theorifice 16 out of the casing C to waste.

In Figs. 2, 8, 9 and 10 there is shown an automatic cut-off switchmounted on the front of the feed chute F. Should the chute F fail tofeed a work piece W to the mandrel, a spring-pressed plate 0-1, beingcontacted by the mandrel M, will be pressed into contact position toclose a circuit through the wires 0-2 to energize a suitable cut-offmeans (not shown) to de-energize the driving motor, thereby stopping theapparatus.

A suitable automatic cut-off switch may be provided to be operated by asuitable tension pulley bearing on the string A, which would stop theapparatus on loss of tension on the string A.

Having described the structural details of my apparatus, I will nowdescribe its operation.

The hopper H being charged with the work pieces W to be polished (Figs.12 and 13), and the string A being disposed as shown in Figs. 1, 4 to 7and 11. The drive disc D is rotated, in the direction of the arrow inFig. 7, causing passage of the portion D-7 of the groove D-S on thefront face of the disc D past the roller F-S of the feed chute P, whichallows the chute F to be projected by its spring F-6 toward the conicalend M-6 of the mandrel M (Fig. 8) thereby mounting the work piece Wwhich has been precipitated by rocking of the hopper ii to the lower endof the chute F and aligned with the discharge throat F-7 of the chute Fwhich is co-ax-ial with the mandrel M. As this action occurs, theportion D-3 of the cam D-2 on the rear face of the disc D causes theroller M-S of the mandrel M to retract the mandrel M to be at rest. Whenthe cam D-Z has passed the roller M-S, the spring 9 (Fig. 2) projectsthe mandrel M to cause its conical cam M-7 to engage the bevel D1 of thedisc D (Fig. 9) to rotate the mandrel M to spin the work piece W mountedthereon. It will be noted (Figs. 4 and 6) that the work piece W is somounted on the mandrel M that its ball groove W2 (Fig. 9) aligned withthe string A carried by the roller R-l.

The racks 23 and 24 (Figs. 5, 7 and 11) on the periphery of the disc Dcause revolution of the tubes 21 and 22, thereby causing the string A tooscillate in the ball groove W-Z of the spinning work piece W. The racks17 (Fig. 11) cause the string A to be fed into and out of the apparatus,thereby supplying fresh string A for the polishing operation.

The racks 23 and 24 are so disposed on the disc D as to revolve thetubes 21 and 22 only when the mandrel is spinning the work piece Wthereon.

The frame R is actuated to cause the rollers R-l to lift the string Afrom the work piece W on the mandrel M, when the mandrel is at rest, thepolishing operation having been completed, and lower the string A aftera new work piece W has been mounted on the mandrel M.

When the rotation of the disc D causes the portion D-4 of the cam D-2 onthe rear face of the disc ID to A1 engage the roller M-5 (Fig. 3), themandrel M is so retracted (Fig. 10) as to cause the polished work pieceW to be stripped from the mandrel M by the abutment l-a. The polishedwork piece W is then discharged from the apparatus by any suitable means(not shown).

Having described my invention, what I claim is:

1. In an apparatus for string polishing work pieces, the combination ofa casing; the. drive disc journaled in said casing; a mandrel rotatablymounted in said casing, and having one end projected from said casing; ahopper for the work pieces, mounted above said casing and having a feedchute with a discharge throat; means actuated by said disc, adapted tomove said chute relative said mandrel to mount a work piece in saidthroat on said end of said mandrel; means, actuated by said disc,adapted to intermittently rotate said mandrel to spinthe work piecemounted thereon; a pair of forwarding rollers mounted in said casing,intermittently rotated by said disc, and adapted to draw the string intothe apparatus; a second pair of forwarding rollers mounted in said.casing, intermittently rotated by said disc, and adapted to draw thestring out of the apparatus, the string being led from said first pairof rollers, over the work piece on the mandrel, to said second pair ofrollers, and being held under tension against the work piece to polishit when the mandrel spins the work piece; and means intermittentlyactuated by said disc, adapted to oscillate the portion of the string inthe apparatus relative the spinning work piece. v

2. An apparatus, according to claim 1, in which said means for movingsaid chute comprises an arm on said chute, slidable relative saidcasing, and biased. toward said casing, a roller on said arm, and a camgroove in said disc co-acting with said roller to cause oscillation ofsaid chute.

3. An apparatus, according to claim 1, in which said means forintermittently rotating said mandrel comprises a peripheral bevel onsaid disc, a conical cam on said mandrel, a journal for said mandrelpivotally mounted in said casing and having a roller, a spring biasingsaid mandrel to cause said conical cam to engage said bevel, and an'arcuate cam on said disc adapted to engage said roller to retract saidmandrel to disengage said conical cam from said bevel.

4. An apparatus, according to claim 1, in which two arcuate racks aremounted on said disc, one of the rollers of each of said pairs ofrollers for forwarding the string has a pinion, and said racks engagesaid pinions, respectively.

5. An apparatus, according to claim 1, in which said means foroscillating the string comprises two hollow shafts journaled in saidcasing, each having an end projecting from said casing, two tubesmounted radially on said projecting ends, respectively, a pinion mountedon each of said shafts in said casing, and two peripheral racks on saiddisc, adapted to rotate said pinions on said shafts, the string beingled from said first pair of forwarding rollers, through one of saidshafts and its tube, and through the other tube and its shaft to saidsecond pair of forwarding rollers.

6. An apparatus, according to claim 1, having a frame verticallyslidably mounted in said casing, an adjustable pin on said disc andadapted to lift said frame, and a pair of rollers journaled on saidframe, and disposed outside of said casing, said rollers havingcircumferential grooves disposed above the spinning work piece, andadapted to lift the string from the work piece when the mandrel is atrest.

References Qited in the file of this patent UNITED STATES PATENTS1,873,129 Johnson Aug. 23, 1932 1,881,162 Aurori et a1. Oct; 4, 19322,121,025 Egger June 21, 1938 2,620,602 Schenk Dec. 9, 1952

